Re: Concurrency via isolated process/thread

[Po Lu]

Ihor Radchenko <yantar92@posteo.net> writes:

> Po Lu <luangruo@yahoo.com> writes:
>
>> Ihor Radchenko <yantar92@posteo.net> writes:
>>
>>> Same with variables - even if some global variable needs to be locked,
>>> it is unlikely that it will need to be accessed by another thread.
>>
>> I doubt symbol value cells will need to be individually interlocked.
>> Emacs Lisp code will need to insert the appropriate instructions to
>> prevent the CPU from undertaking optimizations on load and store
>> operations on those cells when necessary. ...
>
> I had a different simple scenario in mind:
>
> (let ((oldval case-fold-search))
>   (unwind-protect
>     (progn (setq case-fold-search nil)
>       ;; We surely do not want the value of `case-fold-search' to be
>       ;; changed in the middle of `expensive-computation'.
>       (expensive-computation))
>     (setq case-fold-search oldval))

That's easy: case-fold-search can be made local to each thread.